Am I crazy or are the cats pictured under the graph swapped? The cat under the "leftward" bar is curled the right and the cat under the "rightward" bar is curled to the left. Did they just decide that egocentrism in directions doesn't apply to cats?
They say "thus, on average, about two-thirds of cats preferred to sleep on the left side of their body with their left shoulder down", and their image for leftward lateral bias shows this. So I guess leftward means "lying on their left side", not "curling left".
But, they suggest this is because "Upon awakening, a leftward sleeping position would provide a fast left visual field view of objects", which seems suspect. When my cats sleep on their left, it's their left eye that's obscured by their paw, and their right eye that has a better field of view!
They say 'leftward sleeping position would provide a fast left visual field', while showing a cat sleeping on its left side, with its right eye having the best view (left eye with a bad view).
Clearly, there is a contradiction. What's mystifying is that the authors seemingly spent lots of time on this exact directionality concept, yet put this contradiction in.
The way I understand it, they say that animals react better to danger coming from the left side, because the left visual field (of both eyes) is processed by the right hemisphere, which is dominant for threat processing and spatial attention. So, for the cat sleeping on the left side the danger will probably come from the left side of its visual field, while for cat sleeping on the right side it would come from the right side of the visual field. Therefore, sleeping on the left side is better, because the cat will react faster to something coming towards it.
Look at this picture to see how the image from both eyes is processed:
Maybe they never intended for a broad audience, but the paper would be way more accessible if they had included a description like you have here. It was a frustrating read about a well-liked subject, I'm sure I'm not the only one that felt that way.
Not a biologist, but my understanding is that the temporal part of the right eye (the part of the right eye closest to the temple and furthest from the nose) is responsible for processing the inner part of the left visual field, and is directly connected to the right hemisphere (no cross-over required).
I came here to say the same thing. I’ve seen this multiple times today in several places and thought exactly that. Maybe they should have said clockwise (starting at the head) or counterclockwise?
